First thing we need to do is find the area of the whole region, shaded and not.
Since we have the measurements of the height and length, we just multiply those to get 210 ft.
Now we need to find the area of the shaded area. According to the diagram, 6ft is taken off of the height and 4ft off of the length. That leaves us with 8 and 11. Multiplying those together we get 88.
To find the non shaded area, we subtract the shaded area from the total area. 210-88=122
So the anwser is 122ft^2 or the fourth option.